This page explains how Tom Lackaff (USATT# 4387)'s rating went from 1556 to 1547 at the 2012 Rose City Open held on - 10 Jun 2012. The links below take you to pages that describe various aspects of the rating processor.

The rating processor goes through 4 passes in order. The links take you to pages that provide detailed explanations of the calculations during each of the 4 passes.